The Bourne Evolution
by jrams
Summary: Aaron Cross's preoccupation with Dr. Marta Shearing wasn't simply a product of being thrown together in life-threatening circumstances. What his superiors once viewed as an emotional liability may just prove to be his greatest strength.
1. Prologue

Cross is instantly able to recall the exact number of times Dr. Shearing examined him prior to the events of the Bourne Legacy. While this may be just a result of his enhanced mental faculties, I decided to interpret it as a possible preoccupation with his lady doctor :) This fic is an attempt to flesh out some of their history and how it impacts their relationship both during and after the events in the film. Thanks for reading!

* * *

**Prologue**

It had been surreal. The new sense of awareness that crept through his conscious mind was unlike anything he had experienced before. He found himself having new thoughts, ideas and reactions; his daily interactions with his doctors and instructors opened his mind to possibilities he had never imagined.

Movement and reason happened faster and with more accuracy. His fear of tests and physical evaluations eventually faded away, replaced with a voracious need to satisfy his superiors, those who had granted him this seemingly priceless opportunity. Upon achieving operational status, this need manifested itself in a near-perfect performance record, as he completed mission after mission with robotic consistency. It was during this time however, that Aaron Cross first began to feel the bars of his new cage.

No empathy, they said. Not with the soldiers he occasionally worked with and especially not with the people he regularly killed. This was despite the fact that they frequently asked him to complete missions with massive amounts of collateral damage. He privately began to question his orders and his purpose in the program. Was he truly helping his country? Was he helping to do good in the world? When his kill count reached 200, he began to doubt. After blowing apart a health clinic containing women, children and suspected terrorists, he began to know. Byer spoke of being a 'sin eater', but Aaron understood what he really was becoming. He was losing grip on his own identity. His new realm of awareness was turning out to be as much of a curse as it was a blessing, and so he resolved to carve a place for himself outside of the program. He put together the means to exist on his own, stashing money and multiple identities in caches throughout the countries he worked in. The one issue he could not resolve was the chems. They rationed him out so precisely that he had to return to the Maryland clinic whether he liked it or not - although sometimes he did like it, but only when she did his spec work-ups. She was another thing that illuminated the limits of his existence within the program; he was never going to be with a woman like that, in the ways he occasionally fantasized about. As he waited in the parking lot across the street, watching her enter at the facility's front gate, he decided now was as good a time as ever to check in.

Dr. Marta Shearing knew the terms of her employment so thoroughly she felt like she could recite them from memory. It was the most extensive non-disclosure agreement she'd ever signed. She wasn't allowed to know what the program participants did upon leaving her lab, and the longer she worked there, the more she suspected that she didn't want to know. She knew what she was manipulating them to become, but what they actually did with their enhanced bodies seemed a thing apart. Compartmentalizing and rationalizing her actions became a part of her daily routine, most especially when any of the participants checked in. She never asked unnecessary questions or engaged in friendly conversation, and for the most part, neither did the men. Except for number Five. He was a chatty bastard, but she privately considered him to be her favourite. He had demonstrated the full potential of her viral genetic enhancement research. She remembered his first few weeks in the program; his progress was a personal triumph for her, and she looked forward to obtaining his results every time he came to the facility. So when security announced his arrival shortly after she made it in, she thought it was a good start to her day.

Aaron sat still on the examination table, aware of being observed from the other side of the glass. He kept his breathing even and his pulse slow; he never wanted to let on that he was excited to see her. Although he was, and had been since their first meeting. He could remember her smile and clinical touch in the early days of the program and had eventually associated her with his growing mental and physical capacities. It was her work, the chems, so as much as he had come to despise his handlers, he kept her separate from them in his mind. He suspected she distanced herself from the moral quandaries surrounding her research and the participants, but that did not diminish the gift she had given him. To distract himself from his current surroundings, he let his mind drift. Their first encounter was a watershed memory for him - it was when he had first realized his emerging mental acuity.

_She entered through the other door – not the one he came through. Hair up in a bun and wavy bangs falling over her heart-shaped face, she was the most beautiful person he'd seen in months._

_"Hello. I'm going to take some blood, test your reflexes and run some basic cognitive exercises today. Lay down please – I need your left arm." He complied, watching her as she moved around the room, preparing a syringe and swabbing his skin._

_"What's your name doctor?" She looked at him, slightly startled. It left him feeling uneasy, as not many people in the program reacted like that – in fact, no one reacted like that, as if they didn't know what to say to him._

_"I'm afraid I can't discuss that with you.. it's against policy."_

_"Do you always follow policy doc?"_

_"Yes. Now please make a fist, I need a vein to draw blood."_

_"Yes ma'am." His arm showed signs of his recent training regimen; bruises and scabs criss-crossed his skin. She glanced at the marks, muttering under her breath as she tried to find a good vein. He tensed and then relaxed as she completed her work. They moved on, and by the time she finished the cognitive exercises, Aaron had taken note of his fluidity and comfort in speaking with her, as well as her surprise in his responses. She took furious notes and told him of his progress; he had scored much higher on the exercises than expected and she was pleased with his performance. It was the first time anyone had praised him in this way, after a test, and he took it to heart. He left the room with his head a bit higher than when he'd gone in._

Fours years later, he knew his preoccupation with her had moved beyond gratitude and into more dangerous territory – and that it had not gone unnoticed by his superiors. It earned him a stern lecture on the repercussions of forming attachments, which ironically heightened his desire to know her outside of the program. However, in the interest of protecting the both of them, he had clamped down on his feelings for her to convince those watching him that he understood their warning. His medical exams remained the only time he felt he could safely see her, and as she walked in the room, he had to remind himself to act normally.

Marta felt eyes on her the moment she opened the door. The last few visits had seen a change in his behaviour – his normal banter had subsided to wry one-liners that left her feeling slightly bereft, although she could not explain why. His shirt was already off, displaying his considerable physique; going over her notes, she decided to do a brief once-over to check the state of his previous injuries. She recalled a particularly nasty laceration across the inside of his right palm, one that had almost severed the tendons and cost him the use of his hand. Moving to stand in front of him, she reached out to inspect the wound. It was only when she felt the heat of his skin that she realized she had forgotten to put on her latex gloves. She quickly looked up into his face to find him staring back, his eyes guarded. Flustered, she snapped on a pair of gloves and moved back to check his hand. It was halfway healed, with a raised, puckered scab marking his skin. She proceeded to check over the rest of his torso, but found that she couldn't regain her usual clinical demeanor – she was hyperaware of his closeness and heat. As her hands angled his head to examine a cut across his cheekbone, a blush rose up her neck, and his eyes immediately zeroed in on it. A small smirk flickered across his face, but he remained silent. She brusquely finished her once-over and told him she needed to put him under for a full spec work-up. He lay back and let her do as she pleased. When he woke, the examination room was empty except for his cell phone, which was signaling an incoming assignment from Byer. The next time he saw her, months later, her blushes were gone and her detached persona was back in place.


	2. Chapter One

Hello! Thanks for the comments! I definitely appreciate the feedback. This chapter jumps between events in the film, so I'd like to apologize in advance if it seems a little disjointed and/or repetitive. I should note that most of the dialogue in this chapter is straight from the movie and is not my work.

**Chapter One**

* * *

_Kill two birds with one stone Cross. Chems and the doctor. _The stolen Cessna got him southeast through Canadian airspace to his cache in Toronto just as the mass shooting in Maryland made the news. They were burning Outcome to the ground; there was no other explanation. Dr. Marta Shearing's survival meant she was either in deep with Byer or she was just plain lucky. He suspected the latter. It didn't matter - either way, she was the last link he had left to the chems. There was only a narrow window of time in which to track her down; his stock of intelligence-enhancing blues was dangerously low, and he had used the last of his greens the morning before. If she had just been lucky in escaping the shooter, it wouldn't be long before she was dead by some other means. Her life was important to him, he owed her for what she had given him. But right now his priority had to be the chems – no one was going to take that from him. Besides, he wouldn't be of any use to her if he regressed.

Travelling through the night, Aaron crossed the border under a fake name and drove to an address in Montgomery county that he'd found on a building permit under her name. He drove by the gate marking her lane and parked his car in a nearby lot. Dawn was touching the sky as he hiked through the woods up to a decrepit Georgian mansion. His sensitive ears picked up the sound of someone moving around the ground level of the house, preparing a meal. Concealing himself in the brush on the edge of her yard, he decided to wait a few hours to get a better grip on what was happening with this woman. There was no way of knowing who she really worked for, and he was not ready to reveal his continued existence to anyone who could contact Byer. _Time will tell Dr. Shearing._

* * *

Her heart thudded in her chest. The smoke from her burning house left a trail in the clear morning air that she could see in the rearview mirror. Number Five stepped on the gas, pressing her into the passenger seat of the Buick LeSabre. _What just happened? Why is he here? Why were those people trying to kill her? _

"Where are we going?" He ignored her question and snapped out instructions, demanding that she repeat an alias for the two of them. _June Monroe… June Monroe. James and June._

"Is that your name?" He turned incredulous eyes on her, as if he didn't believe the words coming out of her mouth.

"James? No. What? You don't know my name? What do you call me? What do you put on my blood work?"

"Five.." she murmured, feeling vaguely ashamed.

"Five? The number five?" he was disgusted. "Do you know how many times we've met? Thirteen. Thirteen exams over the last four years, and that's what I get, a number? Number Five. Right. Five of what? How many are we?"

"Program participants?" she hesitated.

"That's what you call us?"

"There were.. nine, then six."

"Participants…" he murmured in disbelief. Marta couldn't take this. She sputtered out questions but he shut her down.

"No, look you had your turn! You've been bleeding, and scoping and scraping me since the day we met, it's my turn now. I'm asking the questions, you got it? I need program meds. Where do you keep the chems?"

"I don't have any! I really don't - I don't know anything!"

"Bullshit! That's why they're trying so hard to kill you because you don't know anything? For four years… you can't be that naïve! There's no way you're that naïve!" She couldn't listen to this anymore, he was shouting and she was so scared of what he was saying.

"Let me out of the car!"

He pulled over and laid it out for her. Listening to him describe her slim chances at survival without him made her reevaluate her decision. He really was her only option; too many people had already tried to kill her. They wouldn't stop looking for her now.

"You have to understand… we don't fabricate the chems. That happens downstream."

"Where, what does that mean?" he demanded.

"It means you need live virus to seed adhesion. Cultures are highly reactive, you have to process onsite.." she trailed off at the desperate look on his face.

"Onsite where? _Where is it_?"

"Manila. The Phillipines."

He got out of the car and leaned his head against the trunk. She got out and stood behind him.

"Where do you stand with your dosage?" she asked. He told her, and she blanched at the knowledge that he was still taking the green physical enhancement meds. "You were viralled off physical medication last year. They infected you with live virus which means you're physically stable… you don't need to take them anymore. They locked it in... any physical enhancement is now permanent." She backed up as he turned furious eyes on her.

"You _infected_ me? When was this? Was it that mystery flu where I almost _died_? That was it, wasn't it! Who tells you that this is ok!?"

"No - I do research! I don't administer meds... I don't make policy!"

"No, you just load the gun." He snapped. She turned away in horror, babbling empty excuses. _What had her work been used for? What had she done? _He interrupted her, grabbing her shoulders. "Tell me you can viral off blues!" The desperation in his voice shook her.

"Theoretically, yes. The pills allow temporary adhesion, but to lock it in you need live culture... live _virus_!"

"Do you know how to do that?"

"Yes... but - but I told you, it's on the other side of the planet!" She knew she sounded hysterical.

"That's where we're going. Get in."

Aaron gunned the car down the highway, silently fuming. _Number Five? For fuck's sake. _Marta sat in the passenger seat, staring at her hands. He almost couldn't believe what she had said. Naïve didn't begin to cover it. Although he knew he shouldn't be surprised; she was a scientist and in his experience they tended to be a narrow-minded lot. It wasn't her fault he'd put her on a pedestal all these years. Her voice broke his train of thought.

"So let's say you wanna change the human body... fix a mistake, repair something, improve something. Well if you're gonna reprogram human genetic material, you need a delivery system, and nothing works better than virus. It's like a suitcase. You pack in genetic mutation, infect the body, and the virus loads into the target cells... you've had some very minor alterations made to two different chromosomes. The green side, the physical side, is nothing more than a one and half percent rise in your mitochondrial protein uptake. But with one and half percent, you see this immediate increase in cellular tempo, muscle efficiency, oxygenation..." she trailed off.

"And the blue side?" He prompted.

"Intelligence, obviously, but it's more than that. It's neural regeneration and elasticity, sensory function, pain suppression... it's the most exciting development in genomic targeting in the history of the science-" She abruptly stopped speaking. His mind reeled. To her, he was nothing but a science project. He knew they had been messing with his body, and for the most part he had been happy to let them do it. But this went beyond anything he had imagined. They had altered his _genes. _Glancing over, he was surprised to find her watching him intently, wide eyes full of tears.

"What _is _your name? I'm - I'm sorry I never asked before.. in the lab."

He hesitated - he wasn't sure he wanted her to know. It was her exhausted yet earnest expression that loosened his tongue.

"My name is Aaron, Marta."

* * *

- Manila, 17 hours later -

Aaron felt her hands on him, gently mopping his fevered brow with a wet cloth. He wasn't sure where they were, but they couldn't have made it far from the pharmaceutical factory. She needed to keep moving, there was no time. Pushing her hands away, he struggled upright to look her in the face, his sight swooning around him.

"What-" she choked out.

"There's forty thousand dollars in the lining of my jacket. In this bag are passports, two blanks three ghosts… you take it. There's the guy's watch… look at me. You can make it, you're a warrior, you can make it ok? You stay small, no airports… just stay small like you know. You've done enough for me… you've done enough for me." He stopped speaking as she touched his face with the cloth, shushing him. The room spun in his vision. He thought he was in the grips of another fever dream when he felt her pull him to her chest, rocking him like a child. _What the hell was she doing? _It was unbelievable for her to stay, she had done what he asked her to do. He was viralled off. She needed to take the money and go; they were too close to the people hunting them. It was his fault she was here – and now he was useless, despite his genetically enhanced body. _So much for be all you can be. _He tried to speak again, but instead closed his eyes. There was no way to resist the feeling of resting in her arms, just for a moment. The room seemed to stop spinning, her body anchoring him. _How many times had he thought about her touching him like this?_

"Shhh… shh." Rubbing his back with her free hand, Marta felt the last twenty-four hours crashing in on her. Leaving him was an impossible thought for too many reasons. That he was giving her a chance to get away just reinforced her determination to stay. He owed her absolutely nothing. And yet here he was, giving her the tools she needed to survive at his own expense. _What had she done to him?_ The creeping sense of guilt she had been trying to ignore finally swamped her, as hot and heavy as his body resting on her chest. The memory of calling him number Five made her cringe. Running her hand across his forehead, Marta wished that she had done more for him, said more to him… _anything._ It seemed insane that he had once been a numbered experiment to her, yet now he was the most vital thing, real thing she had left. _How had it all happened so quickly?_ Her mind whirled and she fought to stay calm. There was no reason for him to protect her now and she was going to slow him down. He was too good to let them kill him - soon she would have to let him go. The thought of him leaving made her hold him tighter for a second. His breathing slowed and his body slumped against her.

"Here, lay back. There, that's good Aaron." she whispered as she lowered his head to the dirty pillow. She sat on the floor beside the bed, resting her head close to his face to watch him sleep. His skin had a sickly glow in the yellow light from the street as she traced his profile with her fingers. Afraid of disturbing him, but unable to resist the urge, she quickly leaned in and pressed her lips to his. Come what may, she was determined to get him through the night.

The hours ticked by in a sweaty haze as she bathed his brow and chest with her dwindling supply of bottled water. Every small sound made her flinch and check the door for intruders. Around five o'clock, just as dawn was touching the sky, his fever broke. Marta heaved a sigh of relief. She got up to change into fresh clothes and wash her face. Dizzy, she braced her arms on the sink; tired, red eyes stared back at her in the tiny mirror. _Focus._ There was no way Aaaron was out of the woods yet, so she decided on stocking up on basic medicinal supplies to get them through the next few days. Thinking she had better avoid wasting their precious time, she penned him a quick note and sped out the door.

* * *

_"AARON! RUUUN!"_ Her desperate shriek echoed up through the morning air, snapping him to attention. The fever was gone and his mind was sharp. Grabbing their gear, he was out the window and on the roof in seconds. The sounds of the chase rose up from the street and he followed, sprinting across rooftops to a narrow drop between two buildings. Two officers had her pinned.

"Get down!" Marta obeyed, dropping to her knees as he vaulted over her to take out the second officer. He was pretty sure he had killed the first when he landed on him. There was no time to think about collateral. Down the street and halfway across a footbridge, he spotted a man watching them from another roof. It was the man's stillness and intense scrutiny that gave him away. _Asset. _Aaron knew it had only been a matter time before they called one in. Improvising, he caused a distraction by ripping open a passerby's grocery bag. Ducking down amidst the yelling, he forced Marta over the railing of the bridge, dropping her onto the top of a bus on the street below. He followed her down and pushed her to walk ahead on her own, while scoping the street for the nearest available vehicle. Some idiot had left his bike idling on the side of the road – he was on it and back to Marta in seconds.

"Have you been on a bike before? No? Here, put this on." He waited until the helmet was on her head before he revved up. "Hang on tight." The asset he had spotted earlier rounded the corner as he sped away. Maneuvering his way through the city, he zeroed in on narrow passages to try and lose the growing number of vehicles following them. They burst out onto a major road where he realized that rush hour traffic was in his advantage. The bike could squeeze through openings the police couldn't follow, although the asset was proving to be more resourceful than he'd hoped. The man caught up with them in a stolen police car and he had to shout at Marta to turn her head away; the guy had a Glock trained on them out the driver's window. He swung the bike around, kicked the front wheel over a stone railing and slid down on the chassis to a street below. Marta was gripping his waist hard enough to bruise. Passing a side road, he heard a gunshot just as it entered his thigh. _Motherfucker. _After checking to make sure Marta wasn't hit, he took a hard right in the direction of the shooter. With one hand, he pulled the gun from his belt, released the safety and fired twice at the asset as he crossed behind him at the next intersection. Without pause, he raced on into a complex of warehouses – they had to be near the shore. _Just make it to a boat. _Marta reached down to touch his leg.

"You've been shot! Pull over! Pull over!" she screamed.

"We just need to make it to the water" he tried to reassure her, resting one hand atop hers on his waist. His sight was going black at the edges. _Blood loss. _He focused on the street in front of him, angling the bike down a wide pier just as Marta yelled his name. It was the asset, hot on their tail. This confirmed Aaron's suspicion that the guy was enhanced; he'd shot him twice and it had barely slowed the asset down.

His sight was failing – it was all he could do to keep the bike upright and moving in the right direction. He felt Marta move behind him and scream again, but he couldn't concentrate on what she was saying. The bike tipped under them and he felt the shredding sensation of his skin sliding along concrete. The next thing he knew, Marta was leaning over him, grasping at his hand. He held on, trying to see if she was ok. He knew the light feeling in his head was slowing down his ability to think. _Focus. _More voices, and another set of hands gripped him under the shoulders and heaved him to his feet.

"It's okay, it's okay, they're going to help us… walk!" Marta rasped, her voice rough with pain. He leaned on her shoulder as they struggled across a metal walkway. He felt the ground shift under him. A middle-aged Filipino man walked ahead of them and opened a door leading into darkness. Stairs. He made it to the bottom before the ground rushed up to meet his face.

"Alcohol? Bandages?" Marta frantically mimed the words to the young boy standing in the doorway. He nodded and ran down the hall. Marta turned back to Aaron who lay sprawled across the floor. The small cabin they were in was musty and cluttered with fishing gear. She swept junk off the tiny bed attached to the wall and moved to lift his body. The effort it took to get him up on the bed left her dizzy and dripping with sweat. She braced her shaking hands on his legs to look at the bullet hole in his thigh. Blood stained his pants from hip to knee. _Shit shit shit. _The boy raced back into the room and dropped a first aid kit at her side - all it held was tweezers, gauze and rubbing alcohol. _Good enough. _She worked feverishly, tugging his pants down his legs and pulling the bullet from his thigh, sagging in relief when she saw it was just a flesh wound. It wasn't until she was done cleaning and bandaging him that she realized something wasn't right with _her. _

She couldn't get back up. Strange colours spotted her vision and she couldn't get enough air. Collapsing on her back, sound bombarded her suddenly sensitive eardrums as an overpowering smell of rotting fish made her turn her head and vomit bile. Her mind raced, instantly making a connection. _Oh God. Seed adhesion…live virus._ The boy was still there; his worried face was the last thing she saw before the strange colours pulled her under.


End file.
